The influence of thermally induced cholesteric liquid crystal structural colour for information encryption

Cholesteric liquid crystal (CLC) is particularly remarkable due to its ability to exhibit structural colour. Structural colour materials offer solutions for information encryption that feature good stability, ease of perceivability, and arbitrary patterns. This work investigates the temperature-dependent variation of CLC structural colour and provides a quantitative analysis of the pitch and helix twist power (HTP) at different temperatures, further exploring its potential applications in information encryption. By recording quick response (QR) code patterns in the LC Polymer of the LC cell, single-pattern and dual-pattern LC cells are prepared, and their applications in information encryption are demonstrated. The QR pattern will be hidden or revealed as the temperature changes by CLC in the LC cell. Additionally, dual-pattern encryption requires polarisers to address the crosstalk issue under white light, making the LC cell a safer solution for access control systems. These results lay a theoretical foundation in CLC stimulus-responsive structural colours and offer valuable insights in information security and anti-counterfeiting applications.